Tetrachloroethylene may be prepared by pyrolysis of carbon tetrachloride. Reaction temperatures for pyrolysis of carbon tetrachloride are variously reported as being of the order of 800.degree. C. (See, U.S. Pat. No. 3,364,272 issued to J. W. Ager, Jr.), as temperatures at the high end of the temperature range 600.degree. C.- 1500.degree. C. (U.S. Pat. No. 1,930,350 issued to C. J. Strosacker et al), and as temperatures within the range of 1300.degree. C.-1400.degree. C. (U.S. Pat. No. 2,447,410 to Hampel).
The use of prior art high pyrolysis temperatures generally necessitates high energy input, limited selection of reactor construction materials, and more extensive separation of unwanted by-products.
It is also known to hydrogenate chloro-carbon and chloro-hydrocarbon compounds to compounds having the same number of carbon atoms by the use of elemental hydrogen and copper catalysts at temperatures of 350.degree. C.-550.degree. C. (See, U.S. Pat. No. 2,886,605 issued to H. H. McClure et al).